[Fluctuations in uncorrected visual acuity after refractive surgery using intra-stromal corneal rings]

Refractive surgery is meant to provide early stable and good uncorrected visual acuity. Our main concern in this study was to take special interest in fluctuation in uncorrected acuity within the first three months after implantation of Schanzlin intracorneal ring segments (ICRS) produced by Keravision.

Ten eyes in 6 patients underwent implantation of 2 intrastromal corneal segments for myopias ranging from -1.00 to -3.50 Dipoters. Visual acuity was measured with cytoplegy on day one, on day 8, two weeks, 1 month, and 2 months after surgery. The fluctuations of visual acuity were noted between observations.

Uncorrected visual acuity varied up to 4 lines without an obvious pattern of progression over time. Fifty percent of the eyes had a variation of 2 lines. The best spectacle corrected visual acuity was preserved in all patients.

Corneal topography with measurement of keratometry, intraocular pressure, and examination of the anterior chamber must be studied to identify the parameter that could condition these fluctuations of visual acuity. No parameter was found to predict these variations that may result from individual corneal healing factors peculiar to each patient. The fluctuations of uncorrected visual acuity were relatively important during the 3 first postoperative months. In all patients, final uncorrected visual acuity was always at least 10/10.